On a trip to Thailand accompanying Duterte, Tourism Secretary Wanda Teo insisted the Philippines was a safe destination but said journalists were making the country a hard sell because of their focus on the killings.

"Help us because you know, it's really difficult for me to sell the Philippines, especially when extrajudicial killings becomes the topic," Teo told Filipino reporters following the Duterte entourage.

Teo said tour operators abroad were "always" asking her about the issue, citing Asia and Europe as regions where people were particularly concerned.

"To the media, please tone down a little the extrajudicial killing (reports)," she said.

Teo's call comes after Robredo, in a video played during a United Nations meeting, criticized the spike of extra judicial killings and human rights violations under the Duterte administration.

Police inspect the bodies of two men lying on a sidewalk, who police said were killed after a drug buy-bust operation in Quezon City Sunday. Ezra Acayan, Reuters

"I have a great respect for VP Leni. [But] PH is now becoming a great alternate destination in Asia and the Europe. Yung mga statement na ganun, it really, nahihirapan kami isell ang Philippines," said Teo.

Duterte was elected last year after promising during the campaign to eradicate drugs in society by killing tens of thousands of people.

Police take responsibility for over 2,500 of those deaths during their anti-drugs operations, but reject allegations by local and international human rights groups that police are involved in thousands of mysterious murders of drug users.

Duterte briefly suspended all police from the crackdown in January after it was revealed anti-drugs officers used the drug war as cover for kidnapping and murdering South Korean businessman Jee Ick-joo.

But, after describing the police force as "corrupt to the core," Duterte brought it back a month later and vowed to continue the crackdown until all drug traffickers were off the streets or killed.

Duterte has over the past year become a well-known figure internationally because of the drug war and his caustic rhetoric against critics.

The Philippines, despite picturesque tropical islands and spectacular mountains, has long lagged behind its neighbors as a tourist destination.

This is partly due to decades-long Muslim and communist insurgencies, as well as frequent kidnappings of foreigners by Islamic militants.

Despite the negative impression on the country, Teo was confident tourist arrivals will not wane after China committed to encourage about 1 million Chinese travelers to visit Philippine destinations within the year.

About 5.9 million tourists visited the Philippines last year, compared with 32.6 million for Thailand.